People will always amaze me.

As you described it it's extremely extremely suspicious.
Yet you opened the door to a random stranger trying to enter your flat in the night (?????? maybe it was to look at your old stamp collection, who knows? what else could it be for?)

Yet the only thing you do is to ask public forum on what to do?


Also I would bet that you haven't even bothered reporting that to the police, or put a warning sign in the hallway of the building.

Great!

Well at least we haven't read another topic:
Help I have been stolen or raped or killed (mind you, if you would be dead I doubt you would be posting here).